Automatic telephone circuit and repeater.



0. ADAMS-RANDALL. AUTOMATIC TELEPHONE CIRCUIT AND REPEATER.

APPLICATION IILEI) MAR. 13, 1911.

1,015,768. Patented Jan. 30, 1912.

UNITED STATES PATENT OFFICE.

CHARLES ADAMS-RANDALL, OF NEW'YORIQN. Y., ASSIGNOR TO RANDALL TELEPHONEMANUFACTURING COMPANY, OF AUGUSTA, MAINE, A CORPORATION OF MAINE.

AU'IOMATIC' TELEPHONE CIRCUIT AND REPEATER.

Specification of letters Patent. Application filed March 13, 1 911.

Serial No. 614,187.

To all whom it may concern.

Be it known that I, CHARLES ADAMS-RAN DALL, a citizen of the UnitedStates, residing at New York, in the county of New York and State. ofNew York, have invented certain new and useful Improvements in AutomaticTelephone Circuits and Repeaters; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such aswill enable others skilled in the art to which it appertains to make anduse the same; a f

This invention relates to automatic telephone circuits and repeaters,and has for its object to adapt the repeater to ordinary telephoneexchange uses whereby toll lines now operating unsatisfactorily, can beren dered more etlicient.

This application differs from my two copending applications filed on the13th day of March, 1911, and onthe 20th day of De cember, 1910, andrespectively numbered 614,191 and 598,343 in that no controllers orrelays are employed, and further, in this application, the mainlines areinductively connected, as illustrated.

With these and other objects in view, the invention consists in thenovel arrangement of puts more fully hereinafter disclosedandparticularly pointed out in the claims.

Referring to the accompanying drawing fo'rlning'a part of thisspecification in which the figure is a diagrammatic illustration of asystem arranged in accordance with my invention-4 represents anysuitable transmitter, 2 a local battery associated therewith, and 3 aprimary of the usual induct-ion coil d. 5

represents the secondary of said induction coil which is connected atone end by the wire 6 to the hook lever 7 associated with the contact 8connected bythe wire 9 to the receiver 10 which in turn is connected bythe wire 11 to one side of the condenser 12. The other side of said0011-- denser is connected by the Wire 13 to one end of the transformercoil 14, which coil is connected at its other end by the wire 15 to oneside of the condenser 16 whuse other side is connected by the wire 17 toone end. of the coils of the repeater 18, while, the

a subscriber'at the distant other end of said coils are connected by thewire 19 to the other end of the secondary 5, as shown.

The transformer coil 14 is inductively associated with a companion coil20 connected at one end by the wire 2.1 to oneside of the condenser 22,the other-side of which is connected by the wire 23 to the receiver 24:,which is connected by the wire 25 to the contact 26 associated with thehook lever 27, connected by the wire 28 to one end of the secondary 29of. the induction coil 30, 'the other end of whichis connected by thewire 31' to one end of the coils of the repeater 32. while theother endof said coils is connected by the wire 33 to one side of the condenser34. The other end of said condenser is connected by the wire 35 to theother endof the transformer coil 20, as illustrated. Joined to the wire13 at the point 36 is a wire '37 attached to the switch 38, which makescircuit with the wire 39 joined to the contact member 40 of the repeater18, and associated with this contact "member is a companion member 41joined by the wire 42, to the local battery 43, joined by the wire 44.to the impedance 45, joined by the Wire 46 to the. wire 15, as shown.Likewise, connected to the wire 21 at the point 50 is the wire 51 joinedto the switch ,52 making circuit with the wire 53, connected with thecontact member 54 of the repeater 32, which-- is associated with themember 55 joined by the wire 56 to the local battery 5TconnectedPatented J an, 30,1912.

by the wire 58 to the impedance 59, which in turn is joinedlby the wire60 to the wire 35,

as shown.

The operation of'my invention is as follows :--Aisubscr iber at thestation A calls station B by any suitable calling apparatus (not shown)whereupon each subscriber'removes the re ceivers from their respectivehooks, and make the circuits at the contacts 7 and 8 and 26 and 27respectively. After these contacts are made, speech being utteredintothe transmitter 1, will cause currents in the well known manner toleave one-end of the secondary coil 5 and to traverse the connection'6,contacts 7 and 8, connection 9, receiver 10, connection 11, and to flowinto the condenser 12. Currents similar to these voice caused currentswill flow out of the condenser 12 along the wire 13 through the vcoil14, along the wire 15, into the condenser 16. Similar currents, willflow out of the condenser 16, along the wire 17 through the coils; ofthe repeater 18' and along the wire 19 back to the other end of thesecondary 5. The currents flowing through the coil 14 will inducesimilar cur- 1 rents in coil 20, which currents may be supposed to leavesaid coil at one end along the wire 21 and-to flow into the condenser22. Similar currents will. thereupon flow outof said condenser 22, alongthe wire 23, through the receiver 24, along the wire 25,

across the contacts 26 and 27 along the wire 28, through the secondary29, along the wire 31, through the coils of the repeater 32, alongthe'wire 33, and into the condenser 34. Currentssimilar to these voicecaused currents will thereupon flow out of'said condenser 34- along thewire 35, back to the other end of said coil 20, whereupon the originalspeech will be reproduced in the receiver 24 at the distant station.

The currents from the condenser 16, however, fiowing through the coilsof the repeater 18 will cause said repeater to vary the resistanceacross the contacts 40 and 41, where-- upon currents similar to. theoriginal voice caused currents will flow from the battery 43tlirough thecoil 14,.and reinforcethe.

original voice caused currents traversingsaid coil. 7 This efi'ect, ofcourse, will cause the currents transmitted to the" coil 20 to bereinforced and therefore the speech in the receiver 24 will berenderedlclearer than would otherwise be the case; When it is desired totalk from the stationB to the station A, speech uttered into thetransmitter 60 will "cause currents in accordance with sound waves toleave the secondary 29 .and over the connections shown, traversethecoils of the repeater 32,

i pass. throughthe condenser 34, the coil 20,-

the condenser 22, the receiver- 24, the contacts 26 and 27, and returnto said secondary 29. These currents similar to sound waves traversingthe coil 20 will induce similar currents in the coil 14, and thesecurrents will traversethe condenser 12,,the receiver 10, the contacts 8and 7 ,the secondary 5,

the coils of the repeater 18, and the condenser 16, so'thatthe-saidspeech will be heard in the receiver 10. In the same way, these voicecaused currents from-the station It passing through the coils of therepeater will vary the resistance between the contacts 54 and 55 andthereupon cause currents from the battery 57 to reinforce the originalcurrents traversingthe coil-20. The effect of these latter currents willlikewise reinforce the currents traversing the receiver 10, andtherefore render the speech in said re ceiver clearer than wouldotherwise be the case.

The object of the condensers l2, l6 and 22, 34 in their respective linecircuits, is to form a local shunt circuit of comparatively lowresistance around the coils l4 and 20, to prevent the current from thebatteries 43 and 57 traversing their respective lino circuits.

The coils 45 and 59 are of low resistance to the battery currents and ofhigh impedance to the alternating telephone cur rents in order toprevent the latter from traversing the local shunt circuits so thattheir fullenergy may be available on the main line circuits.

In some cases I find excellent results can be obtained by omitting oneor both of-the impedances 45 and 59, and inorder to accomplish this Ihave provided the switches 70 and 71, and the shunts 7 2 and 7 3 around.series with saidline; atransformer coil in serieswith said line; arepeater coil in series with said line; a second main line; a repeatingcircuit joined in shunt to said'first named line between saidcondensers; and a second transformer coil inductively asso ciated withsaid first mentioned coil and in series with said second main line,substantially as described.

2; In a telephone system, the combination of a main line; a pair ofcondensers in series with said line; a transformer coil in serles Wltllsaid line between said condensers; a repeater coll 1n series with saidline; a second main line; a repeating circuit provided with an impedancejoined in shunt to said first named l1ne between said condensers; andasecond transformer coll 1ntioned'coil and in series with said secondmain line, substantially as described.

3. In a telephone system, the combination of a plurality of v main linesinductively associated; a repeaterin series with each of -SaldJlHBS; acondenser in series with each of said lines; and a repeating circuitjoined in shunt with each of said lines; substantially as described.

-ductively associated with said first Inen- 4. In a telephone system,the-combination of a plurality of main lines inductively associated; arepeater in'series with each of said lines; a pair of condensers inseries with having an impedance joined in shunt with 10 each ofsaidlines; and a repeating circuit I each of said lines, substantially asdescribed. joined in shunt between'said condensers with r In testimonywhereof, I aflix my sigeach of said lines, substantially'as described.nature, in presence of two witnesses.

5. In a telephone system the combination of a plurality of mainlinesiinductively asso- CHARLES ADAMS-RANDALL ciated; a repeater inseri'eswith each of said Witnesses: l v 1 lines; a palr of condensers inseries with 1 I. SMITH,

each of said 1ine's;-and a repeating circuit FREDERICK B. BLAGKMAN.

copies at thilhatent may be obtalnedfor five cents each, by addressingthe fcornmlssioner of Patents,

' Washington, D. 0.

